added class files
added isPowerOn method, possibility to use multiple power pins, and Dummy signals powerOn() at Boot.booted
use ArbitratedReadC instead of ResourceReadC
completly rewritten driver with better arbitration. Also usable with STS21
added conversion modules for sht2x. Simplified ucmini test app a bit
added conversion modules for atm128rfa1 temperature sensor
added license
generic error in Resource/ResourceConfigure interaction

ResourceConfigure is called outside atomic.

fix issue #164
arbitration futher fixes
Release spi bus resource before we return EBUSY in the rf212/rf230 radio driver.
fix whitespace changes
rfxlink: release the SPI bus after an unsuccessfull transmit attempt (do the same fo the other rfxlink radios)
Fixed whitespaces and licenses
Merge branch 'ucmini_sensors'
msp430: tweak msp430hardware, better explanation of MSP430_HAS_I2C.
Merge branch 'arbitration-configure-fix'
4bitle: return type of Send.cancel should be error_t

was uint8_t but should have been error_t to match the
interface of AMSend.cancel.
Expose the LowPowerListening interface in ActiveMessageC for platforms
where this was not yet done. The remaining platforms where this is not
exposed are: eyesIFX (Tda5250, LowPowerListening is not implemented) and
tinynode (XE1205, has special LPL component and interface).
Remove confusing default channel define from RFxxx register definitions (from Elena Chervakova)
Escape serial CRC, allow limited retries.